1. Field of the Invention
The present invention relates to a high density or compact storage system that makes most efficient use of available floor space by providing storage units that are movable in such a way so as to define a single movable access aisle for all of the units. That is, any two movable storage units may be positioned to be directly adjacent each other at one side of each with access provided by an aisle on an opposite side of one of the units. If access is desired on the other side of that unit, initially directly adjacent the other unit, the first unit is merely moved to a position spaced from the other unit thereby moving the access aisle.
The present invention has particular utility as a compact storage unit that utilizes, as its basic components, a wire shelving system known as the SUPER ERECTA shelf system made and sold by InterMetro Industries, the assignee of the subject invention. However, the novel components of the subject invention may be used equally well in other storage systems in which the storage units are constructed in many different fashions.
Furthermore, the present invention provides particular advantages in application such as in the food service and hospital industries where sanitation is of prime concern.
2. Description of the Prior Art
Storage systems in which storage units are mounted for translational movement on a base, thereby providing a movable aisle offering access to each of the units and thereby making efficient use of floor space, are known. U.S. Pat. No. 3,801,176 (Higbee) relates to a typical storage system of this type, which is also known as an "active aisle" system. The storage system shown in the Higbee patent includes a pair of inverted, generally V-shaped rails that are mutually parallel and are securely mounted on a base platform such as a floor. A number of storage units or carts are mounted on wheels, each of which has a V-shaped groove formed in its circumference. Two wheels on each cart mate with, and are guided on, one of the two V-shaped rails. The wheels on each cart are fixed against swiveling movement, which is said to eliminate the need for directly attaching the guide rails to the floor.
The system shown in the Higbee patent has several notable disadvantages. More particularly, in applications in, for example, the food service and hospital industries, it is difficult to maintain sanitary conditions on and about the rails that are mounted on the floor since they readily collect undersirable foreign matter such as dirt and grease. The rails mounted on the floor also may constitute a safety hazard since operators and users of the system may strip or stumble over them. Additionally, users of the system may want to take independent wheeled utility carts into the active aisle to transport items to and from the storage units. However, guide rails mounted on the floor interfer with free movement of such utility carts into the active aisle.
Other known storage systems are operable on a flat base or floor on which a number of storage units are supported for translational movement. For example, U.S. Pat. No. 766,660 (Bohannan) relates to such a system in which each storage unit is provided with four wheels at its bottom that ride on the floor, while, at its top each unit is provided with a number of trolleys that override and are guided by two mutually guide rods. While the system of the Bohannan patent does not mount its guide rails on the base platform or floor, and thereby eliminates the disadvantages associated with guide rails of this type, it is nevertheless characterized by other disadvantages. More particularly, if there is any deviation in the flatness of the floor or deviation from a straight line by the guide rods, proper engagement of the trolleys on the guide rods properly to guide movement of the storage units not be maintained. Moreover, since the trolleys override the guide rods, it is necessary in assembling the system to either lift the storage units and associated trolleys up properly to position the trolleys on the guide rods or to mount the guide rods after the storage units are in position. Alternatively it is necessary to install the trolleys on the storage units after the storage units and guide raids are in position. However, a complicated arrangement for securing the trolleys to the storage units is required since the relative positions of the trolleys and guide rail may result in forces during storage unit movement that would tend to pull the trolley out of the storage unit. Moreover, as disclosed, the guide rods are secured to interior walls of the building or other structure in which the storage systems is mounted. Thus, the building itself must modified to accommodate the system as described.
Still other compact storage or high density systems are shown in U.S. Pat. Nos. 3,957,322 (Mastronardi et al.), which relates to a means for selectively shifting storage units; 4,432,589 (Sattel), which relates to devices for lighting the active aisle wherever it may be positioned; and 3,762,335 (Baker, Jr., et al.), which relates to a system in which storage units are mounted for movement on air cushions and are guided by rollers having a vertical axis and confined for movement in an upwardly open U-shaped channel secured to the floor or base platform.
Commercially available high density or compact storage systems are marketed by Amco Corporation, 901 North Kilpatrick Avenue, Chicago, Ill., Market Forge, Everett, Mass. 02149; Ames Color-File, 12 Park Street, Somerville, Mass. 02143; and, InterMetro Industries Corporation, North Washington Street, Wilkes-Barre, Penn. Each of these commercially available high density storage systems is generally of the type shown in the Higbee patent.